2008 GMC Sierra: Fit For A Foreman

This Oil Rig Has Four Wheels and 900 HP

Even though 99 percent of North America’s population chooses to drive gas-powered vehicles, you can still find select areas where diesels dominate the landscape. Take the oilfields of the Great White North for example. Nils MacArthur resides in the oil-rich province of Alberta, Canada, makes a living in the oil industry, and (as is the norm in this region) drives a diesel. “There aren’t too many gas jobs running around up here,” he told us. “Anywhere there’s oil, there’s diesel trucks.”

Because Nils’ ’08 GMC Sierra is his lifeline out in the field, he initially built it to better handle the type of terrain it was often subjected to. Then, once the suspension lift, air springs, and mud terrain tires added the off-road functionality he was after, he focused his attention on the powertrain. As it turns out, through his longtime readership of Diesel Power, he was intrigued by the kind of work Empire Diesel Performance was doing (Aug. ’09 and Feb. ’11) and decided he wanted a quick-spooling, high-powered truck.

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| The ground-up LMM engine build took place at Empire Diesel Performance. Billet main bearing caps, Empire main studs, R&R Racing Products’ billet-steel connecting rods, 15.5:1 hard-anodized Ross Racing pistons that feature Empire’s proprietary bowl design, and an Empire Stage 1 camshaft round out the bottom end. Up top, the heads were treated to mild street porting, upgraded valvesprings and push tubes, 100-percent-over injectors from Exergy Engineering, and H-11 head studs. One of PPE’s Dual Fueler CP3 systems was installed to support the larger injectors, and a FASS Platinum series fuel system takes care of low-pressure fuel supply. Replacing the factory intercooler is an all-aluminum version from PPE.

After making the 1,300-mile journey to Empire’s Iowa-based facility, the LMM Duramax was transformed into a rock-solid version of its former self, the Allison transmission was bulletproofed, and the truck left with a 900hp-capable package under the hood. With a compound turbo arrangement sourced and fabricated by Empire and a modifications list that reads like a PPE catalog, it’s now a completely different animal.

Back on oilfield duty, Nils says the truck fits right in. “At any given time, you can have four to five heavily modified diesels on one jobsite, so I enjoy it,” he told us. In the end, what’s not to like about a truck that can go anywhere, do anything, make 900 hp, and break the tires loose at 80 mph? Now fully submerged in the diesel performance culture, Nils plans to retire the truck from the oilfields next year and turn up the wick even more.

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| With the DSP5 switch set to its second hottest performance position and the 37-inch BFG mud terrains on the truck, Nils’ big Duramax still made an impressive 890 rwhp on a chassis dyno. Adding some boost to the mix via wastegate tuning could yield well north of 900 rwhp.